When possible, a tour of duty should offer an employee the possibility of a breakout entrepreneurial opportunity. This might involve building and launching a new product, reengineering an existing business process, or introducing an organizational innovation.

The interesting thing is that the tour-of-duty really is a shorter term commitment on both parts. There is no assumption made on either side of the work relationship that it will be extended beyond the tour. From the perspective of the company this means good employees will need to be re-recruited within a known timeframe, and that mediocre employees simply may not have their tour renewed. From the perspective of the employee this means that if the company has been a good one to work for, they will want to be sure to impress them with their accomplishments and not take permanent employment for granted. And time working for not-so-great companies can come to a natural end once the tour-of-duty is complete.

The tour-of-duty approach works: The company gets an engaged employee who’s striving to produce tangible achievements for the firm and who can be an important advocate and resource at the end of his tour or tours. The employee may not get lifetime employment, but he takes a significant step toward lifetime employability. A tour of duty also establishes a realistic zone of trust. Lifelong employment and loyalty are simply not part of today’s world; pretending that they are decreases trust by forcing both sides to lie.

Why two to four years? That time period seems to have nearly universal appeal. In the software business, it syncs with a typical product development cycle, allowing an employee to see a major project through. Consumer goods companies such as P&G rotate their brand managers so that each spends two to four years in a particular role. Investment banks and management consultancies have two- to four-year analyst programs. The cycle applies even outside the business world—think of U.S. presidential elections and the Olympics.

It’s an interesting idea but I’m not sure it would work well at scale. Software development lifecycles are a lot shorter than two-to-four years these days. Organizations cannot realistically commit to keeping employees working on particular project or technology for that long.

One important issue that the article does raise is that employment very often does entail a tour-of-duty even when it isn’t explicitly stated. Engineers and Project Managers generally want to stick around to see their product developed and launched. At the end of a big project, employees – especially your best employees – will be thinking, what next? And it is important to recognize the approaching end to a particularly substantial piece of work, and the need to re-recruit your highest performing employees for another tour – even if that’s not what you call it.